What is the recommended management for patients with Right Bundle Branch Block (RBBB) at baseline who require a pacemaker after Transcatheter Aortic Valve Replacement (TAVR)?

Management of RBBB at Baseline Requiring Pacemaker Post-TAVR

Patients with pre-existing RBBB undergoing TAVR who develop high-degree AV block require permanent pacemaker implantation before discharge, and maintaining transvenous pacing capability with continuous cardiac monitoring for at least 24 hours post-procedure is essential given the up to 24% risk of developing high-degree AV block. 1

Risk Profile and Monitoring Strategy

Pre-Existing RBBB Confers High Risk

• Pre-existing RBBB is a well-established predictor of permanent pacemaker (PPM) requirement after TAVR, with rates of high-degree AV block reaching as high as 24% during hospitalization 1
• This risk persists for up to 7 days post-procedure, with greater latent risk associated with self-expanding valves 1
• Pre-existing RBBB is associated with increased all-cause and cardiovascular mortality post-TAVR 1

Immediate Post-Procedural Management

• Maintain transvenous pacing ability with continuous cardiac monitoring for at least 24 hours, irrespective of new changes in PR or QRS duration 1
• A durable transvenous pacing lead (e.g., active lead from right internal jugular vein) should be secured prior to leaving the procedure suite 1
• If the transvenous pacemaker is removed after 24 hours, recovery location (step-down unit or ICU) and indwelling vascular access must accommodate emergent pacing capability 1

Indications for Permanent Pacemaker Implantation

Class I Indication (Strongest Recommendation)

• New symptomatic or hemodynamically unstable AV block that does not resolve requires permanent pacing before discharge 1
• Persistent high-degree AV block mandates PPM implantation 1

High-Risk Scenarios Requiring PPM

• Transient or persistent procedural high-grade AV block in patients with prior RBBB is an indication for permanent pacing in the vast majority of cases, with anticipated high ventricular pacing requirements at follow-up 1
• Recurrent episodes of transient high-grade AV block in the intraoperative or postoperative period warrant PPM consideration prior to discharge regardless of symptoms 1

Timing and Procedural Considerations

Optimal Timing

• The median time to PPM implantation after TAVR ranges from 2 days to several weeks, with a median of approximately 3 days 1
• It is preferable to separate the TAVR and PPM procedures to allow for informed consent and appropriate procedural setup 1
• Same-day PPM implantation may be reasonable when persistent complete heart block occurs in patients with pre-existing RBBB, provided informed consent has been obtained and appropriate teams/equipment are available 1

Temporary Pacemaker Management

• For patients with transient or persistent high-grade AV block, the temporary pacemaker should remain in place for at least 24 hours to assess for conduction recovery 1
• High-degree AV block persists beyond 48 hours in 2% to 20% of patients 1

Predictive Factors and Risk Stratification

Clinical Predictors of PPM Need

• Baseline first-degree AV block (prolonged PR interval) independently predicts significant pacing requirements (OR 2.4) 2
• QRS duration >140 ms independently predicts pacing dependency (OR 4.3) 2
• Length of membranous septum <8.49 mm is the strongest predictor of PPM need within 30 days, with 98% of patients with LMS <7 mm requiring PPM 3

Atrial Pacing Test

• Rapid atrial pacing up to 120 bpm immediately post-TAVR can predict PPM need: patients who develop second-degree Mobitz I (Wenckebach) AV block have a 13.1% PPM rate at 30 days versus 1.3% in those without Wenckebach (negative predictive value 98.7%) 1

Prophylactic Pacemaker Strategy

Evidence for Prophylactic Approach

• Prophylactic PPM implantation prior to TAVR in patients with baseline RBBB is safe, effective, and reduces hospital length of stay (2 vs 4 days) 2
• Without prophylactic PPM, 67.2% of RBBB patients required urgent PPM after TAVR 2
• 63% of patients with prophylactic PPM demonstrated significant pacing requirements (>10% ventricular pacing) at 12 months 2

When to Consider Prophylactic PPM

• Consider prophylactic PPM in patients with RBBB plus first-degree AV block and/or QRS >140 ms 2
• Discuss potential for PPM and obtain consent in clinic where feasible 1

Long-Term Outcomes and Follow-Up

Pacing Dependency

• At follow-up, 52% of patients with PPM post-TAVR are continuously paced, but 22% recover AV conduction and no longer require pacing for rate support 1
• This recovery does not necessarily mean pacing is unnecessary, as intermittent AV block may persist 1

Mortality Considerations

• New RBBB after TAVR is associated with increased late all-cause and cardiac mortality independent of whether PPM was implanted 1
• Early PPM for new bundle branch block is not protective against increased mortality 1

Critical Pitfalls to Avoid

• Do not remove transvenous pacing capability in the first 24 hours post-TAVR in patients with pre-existing RBBB, even without new conduction changes 1
• Do not discharge patients with recurrent transient high-grade AV block without PPM implantation 1
• Do not assume that absence of immediate post-procedural conduction disturbance eliminates risk—delayed AV block can occur up to 7 days post-procedure 1
• Ensure emergent pacing capability is available if temporary pacemaker is removed before 24 hours 1